Related Experiment Video
Updated: Oct 26, 2025
Generation and Expansion of Primary, Malignant Pleural Mesothelioma Tumor Lines
Published on: April 21, 2022
Prevalence of mesothelin expression in peritoneal disease from colorectal and appendiceal cancers
Dong H Yoon1, Ahmad Ibrahim2, Sergei Tatishchev2
1Division of Colorectal Surgery, Department of Surgery, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
Background:
Mesothelin is a cell surface glycoprotein overexpressed in 28%-58% of colorectal cancer (CRC). We hypothesized that CRC mesothelin expression contributes to peritoneal spread and that it is selectively overexpressed in those with peritoneal metastasis versus distant metastasis.
Methods:
This case-controlled study involved mesothelin immunohistochemistry staining of tumor specimens from patients with metastatic CRC/appendiceal cancers between 2017 and 2019. Staining reactivity was graded from trace to 4+ (low ≤1+; high >1+). Staining patterns were characterized on global (focal/patchy/diffuse) and cellular (apical/cytoplasmic) levels. Immunostaining of normal mesothelial cells served as internal control.
Results:
Thirty-one patients were identified: 11 peritoneal (study) and 20 distant metastasis (control). The control group did not include appendiceal cancers. The study group had greater proportion of high staining reactivity (55% vs. 5%; odds ratio [OR] = 20.4, 95% confidence interval [CI] 1.96-211.8). The study group had more diffuse (36% vs. 0%; OR = 22.2, 95% CI 1.1-465.3) and cytoplasmic staining patterns (73% vs. 28%; OR = 6.9, 95% CI 1.3-37.2).
Conclusion:
Mesothelin expression is higher in CRC/appendiceal cancers with peritoneal metastasis than those with distant metastasis. Immunohistochemistry staining patterns suggestive of propensity towards peritoneal metastasis include diffuse and cytoplasmic staining. Mesothelin may be a potential target for novel treatments of CRC/appendiceal carcinoma with peritoneal involvement.
